No worries. Quaife have dimensions drawings for all their diffs, so I can always check if it ends up being a 6 bolt.Yeah only the ring gear. Not sure on the ep71 unfortunately.
I get the impression they can be swapped separately. I guess they "should" be a matched pair as these boxes are now quite old, they would have worn to each other. Not sure how much difference that would really make though as the diff would have new bearings and be re-shimmed, so would probably sit in a slightly different place anywayare the ring gear and pinion supposed to be a "set" or can they be used/swapped independently?